As mobile phones are becoming smaller, all arrangements that help reduce their size are recommendable. As regards antennas, an advantageous solution is a PIFA type (planar inverted F-antenna) structure. It is effective with respect to its size, and it does not create a protruding part in the phone. In an ordinary mobile phone structure, there is provided a speaker at the same end with the antenna, according to FIG. 1. Figure shows a mobile phone MS including a circuit board 105, the top surface whereof is coated with a conductive layer. The conductive layer forms, among others, the ground plane of the antenna. A PIFA type antenna comprises a radiating plane 101 that is somewhat higher than the ground plane. Beside the radiating plane, there is a speaker capsule 102, from which the sound is led to apertures provided in the mobile phone shell.